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120 Cards in this Set
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- application of water on the surface and sub-surface to supplement natural precipitation essential for plant growth.- the application of water to create a condition in the soil that is favorable for plant growth.-the controlled application of water for agriculture through man-made systems. |
Irrigation |
- supplement natural precipitation - create a condition -controlled application |
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-Removal of excess water in the soil to create conditions suitable for plant growth.-removal of excess water either from the ground surface or from the rootzone. |
Drainage |
-excess water in the soil.
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PD 1067 |
Water Code of the Phillipines |
All water belong to the state. |
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Objective of Irrigation |
1. To supply the moisture essential needed by the crop 2. To cool the soil and the atmosphere thereby provide better crop environment. 3. To reach excess salts in the soil. 4. To improve groundwater storage. 5. To facilitate continuous cropping. 6. To enhance fertilizer application(fertigation) |
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Categories of irrigation method in the Philippines |
NIS(National Irrigation System) CIS(Communal Irrigation System) PIS(Private Irrigation System) |
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unconsolidated mineral or organic material on the immediate surface of the Earth that serves as a natural medium for the growth of the plants. |
Soil |
Uncosilidated mineral or organic material |
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Plants |
-are fundamental to agricultural production because they supply essential plant requirement for plant growth including: -water -nutrients -anchorage -oxygen for roots - moderated temperature |
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Methods of Tap Water: Gravity |
Source of water is higher than the service area(leveling survey) |
-Flooding -Furrows -Siphon Tubes |
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Methods of Tap Water: Pumping |
Source of water is lower than the service than the area(leveling area) |
-shallow tubewalls(deep wells) -surface water pumping(river/reservoir/etc) -pressurized irrigation system( sprankler dry) |
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Structure |
-Grouping or arrangement of soil particles -arrangement of sand, silt and clay particles with aggregrates |
Influences -water and air movement -biological activities -root growth -seeding emergence |
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Soil Structure |
1. Granular 2. Blocky 3. Platy 4. Massive 5. Single Grain |
-soil organic matter generally bind particle into stable aggregrates |
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-density of the solid soil particles and does not include pores(air and water) spaces |
Particle Density |
Mineral soil have 2.65 |
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-density of a volume of the soil as it exists naturally; including pore spaces and organic. |
Bulk Density |
It ranges 1.0 to 1. 8 g/cc |
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-a measured of the soil that holds air and water -it is expressed as a % - includes small and large
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Soil Porosity |
Note -if all voids are filled by water, the soil is saturated: otherwise, unsaturated -if all voids are filled with air, soil is said to be dry |
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-is the ease with which air, water and roots move through soil |
Permeability |
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-indicates the amount of water contained in the soil; measured either by mass or volume. |
Soil moisture content |
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-water that will readily move out of the soil if favorable drainage is provided |
Gravitational Water |
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- water retained in the pore spaces of the soil after gravitational water wave removed -includes most water taken up by the plants |
Capillary water |
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-water on soil grains not capable of significant movement by action of gravity and capillary forces; -water not available for plants. |
Hygroscopic Water |
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-causes the dissimilar particles and/or surfaces to cling to one another |
Forces Acting on Soil Water: Adhesive Water |
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-causes the similar or identical particles/surfaces to cling to one another |
Forces Acting on Soil Water: Cohesive Force |
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-due to the effect of the gravity |
Forces Acting on Soil Water: Gravitational Force |
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-caused by salt or iron concentration differences or gradients -water moving between roots and soil |
Forces Acting on Soil Water: Osmotic Forces |
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-condition in which all pores are filled with water |
Saturation/Maximum Water Holding Capacity |
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-moisture retained after draining gravitational; |
Field Capacity |
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-moisture content of the soil which plants growing will wilt because the so can no longer supply water at a sufficient rate to maintain turgor |
Permanent Wilting Point |
15 bar |
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-moisture content of the soil is held so tightly and appearing as a very thin film of water around a soil particle and may move away through vapor transfer |
Hygroscopic Point |
10000bar |
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-aid in cementing particles of clay silt and sand together with aggregates which increses the water holding capacity- adds vital nutrients to the soil |
Organic Matter |
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Portion of the root zone where the extracts majority of its water |
Effective root depth |
Depends on: plant species/ water uptake/ stage of crop growth |
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-plant available water extracted from the soil must be monitored |
Crop Water Use |
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-depends on the growth stages of the crops |
Sensitivity to drought stress |
ex, silking stage and knee high stage pf corn apply water during the critical stage |
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-refers to the soil depth from which the bulk of the roots of the crop extracts most of the water needed for evapotranspiration |
Effective Root Depth |
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-entry of water into the soil after rain or irrigation |
Infitration |
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-after soil profile welting, the subsequent movement of additional water downward through the soil |
Percolation |
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-measurement of the rate of water movement expressed in cm/hr |
Hydraulic conductivity |
Factor that control hydraulic conductivity -soil texture -structure -density -porosity |
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-the velocity or speed at which the waters enters into the soil |
Infiltration rate |
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-soil property which determines the infiltration rate -the maximum rate of infiltration of a soil in a given condition |
Infiltration Capacity |
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-lateral movement of water into soil or substrata from a source of supply such as reservoir or irrigated canal |
Seepage |
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-refers to the hydrostatic pressure in excess of amount atmospheric pressure which can build up in living, walled cells. |
Turgor Pressure |
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The ratio of volume of water to volume of voids |
Degree of saturation |
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The ratio pf the volume of voids to the volume of solids, expressed in decimal |
Void Ratio |
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The ratio of the bulk density of the soil with the density of water Ratio of the dry mass to water with volume equal to the total volume of the soil (total volume of soil) |
Apparent Specific Gravity |
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The ratio of the particle density of the soil with the density of water |
Real Specific Gravity |
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Can be accomplished by various direct methods based on removal of the water from a sample. |
Measurement of Soil Moisture |
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Weighing a wet sample, removing water by oven drying then reweighing the dried sample |
Gravimetric Method |
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-removing water from the sample of evaporation, reaching, or chemical reaction |
Direct methods |
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Include measuring soil property affected by soil water content -specifically, electrical and thermal conductivity and electrical capacitance of porous materials |
Indirect Methods |
Another Measurement of Soil Moisture Method . Resistance Method -electrical Resistance Blocks -Tensiometer |
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Water impounding through small farm reservoir/SWIR, rain making or cloud seeding |
Rainfall |
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Through impounding of water |
Floodwater |
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Water found in rivers, creeks and lakes |
Inland water |
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Shallow and deepweell/aquifers(continued and uncontinued) through pumping and pressures. |
Groundwater |
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Amount of rainwater that falls directly on the field and is well by the crop for growth and development excluding deep percolation, surface, runoff and interception |
Effective Rainfall |
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The process by which precipitation reaching the earth's surface is returned to the atmosphere a vapor through evaporation from wet surfaces and transpiration by plants |
Evapotranspiration |
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Transfer liquid into the atmosphere |
Evaporation |
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Process through which water vapor passes into the atmosphere through the tissue of living plants. |
Transpiration |
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Geogolic formations having both porosity and permeability |
Aquifers |
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source of water is higherthan the service area ( levelingsurvey) |
Gravity |
Methods of Irrigation -- Flooding − Furrows − Siphon tubes |
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source of water is lowerthan the service than the area (levelingsurvey) |
Pumping |
Methods of Irrigation − shallow tubewells (deep wells) − surface water pumping(river/reservoir/etc) − pressurized irrigation systems(sprinkler/drip) |
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−used in small-scale upland farming. −limited to small plots with easily accessiblesource of water.−size of plot depends largely upon its distancefrom the source, and the time that it takes to fillthe can at the source. |
Watering can |
Methods of Irrigation BY OVERHEAD IRRIGATION - the soil is moistened in much the same way asrain |
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− can be used if there is a piped waterdistribution system where a hose pipe canbe connected to a tap or outlet and there isenough pressure in the water as it emergesfrom the hose pipe. − Major disadvantage: the cost of the watersupply. |
Hose pipe |
BY OVERHEAD IRRIGATION |
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−the application of water to the surfaceof the soil in the form of spray,simulating that of rain. |
• Sprinkler Irrigation |
BY OVERHEAD IRRIGATION |
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−accomplished by running water through smallchannels or furrows while it moves down oracross the slope of the field.−The water sips into the bottom and sides of thefurrows to provide the desired wetting.−Careful land grading for uniform slopes isessential with this method. |
• Furrow irrigation |
Methods of Irrigation FURROWS- wets only a part of the ground surface - - small parallel channels,made to carry water in order toirrigate the crop |
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− a variation of the furrow method and it usessmall rills or corrugations for irrigating closelyspaced crops, such as small grains andpastures. − The water seeps laterally through the soil,wetting the area between the corrugations. |
• Corrugation irrigation |
Methods of Irrigation FURROWS |
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− Water is applied from field ditches to guideits flow −difficult to attain high irrigation efficiencyusing this method −low initial cost of preparing the land. |
• Ordinary Flooding |
Methods of Irrigation BY FLOODING- wets the entire land surface |
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field is divided into a series of strips by borders orridges running down the predominant slope or onthe contour. − water is released into the head of the border. Thewater, confined and guided by two adjacentborders, advances in a thin sheet toward thelower end of the strip. |
• Border-strip flooding |
Methods of Irrigation BY FLOODING - wets the entire land surface |
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−Water is supplied to level plotssurrounded by dikes or levees. −useful on fine-textured soils with lowpermeability, it is necessary to hold thewater on the surface to secure adequatepenetration. |
Level-border or basin irrigation |
Methods of Irrigation BY FLOODING - wets the entire land surface |
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− involves controlled flooding from field ditchesalong the contour of the land, which allowsthe water to flood down the slope betweenfield ditches without employing dikes orother means that guide or restrict itsmovement. |
• Contour-ditch irrigation |
Methods of Irrigation BY FLOODING - wets the entire land surface |
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BY DRIP OR TRICKLE IRRIGATION- water is directed to the base of the plant.- Water is applied to the soil through small orifices (emitters): designed to dischargewater at 1 to 8 liters per hour. - Water is delivered to the orifices through plastic pipelines laid on the soil surfaceor buried. - rate of discharge: determined by the size of the orifice and the pressure in thepipelines.- beneficial for young orchards, vineyards, closed-spaced perennials, and othercrops of high value and in areas where water is scarce or has a high salt content. - highly efficient water utilization, but very expensive |
DRIP OR TRICKLE IRRIGATION
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Methods of Irrigation BY FLOODING - wets the entire land surface |
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the surface is rarely wet since thewater is supplied from the soilunderneath. - requires complete control of the watertable so that the root zone is keptrelatively free of excess water but iscontinually supplied with capillarymoisture during the cropping season |
SUB-IRRIGATION |
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Need for drainage |
•During heavy rainfall the uppersoil layers become saturatedand pools may form. •Water percolates to deeperlayers and infiltrates from thepools. |
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Sources/Causes of excess water: |
•rainfall •high water table •over-irrigation •runoff/seepage from adjacent farms |
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• improves soil structure • the productivity of soils • facilitates early plowing and planting • lengthens the crop growing season • increases the depth of root zone soil thereby provides more available soilmoisture and plant food • improves soil ventilation • increases water infiltration into soils • favors growth of soil bacteria • leaches excess salts from the soil |
Israelsen (1962) noted that adequate drainage: |
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- excess water flows from the farmers' fields to swamps or tolakes and rivers;- often inadequate and artificial or man-made drainage isrequired |
•Natural |
Types of Drainage |
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surface or subsurface drainage |
•Artificial - |
Types of Drainage |
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• field drainage system (quarternary and tertiary or collector drains)• secondary drains or laterals• outfall• recipient water |
Components of a Drainage System |
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•the removal of excess water from the surface of the land;•accomplished by shallow ditches, also called open drains• shallow ditches discharge into larger and deeper collector drains •In order to facilitate the flow of excess water toward the drains,the field is given an artificial slope by means of land grading |
Surface Field Drainage |
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- achieved by plowing land toform a series of low beds,separated by parallel fielddrains.The soil type largely influencesthe width of bed to be used.The furrows drain to collectionditches. |
• Bedding System. |
Surface Field Drainage |
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• forming the land surface bycutting, filling and smoothing itto predetermined grades, sothat each row or surface slopesto a field drain |
Land grading |
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− This system is adapted toareas that have depressionswhich are too deep or toolarge to fill by land leveling.The ditches meander fromone low spot to another,collecting the water andcarrying it to an outlet ditch. |
•Random Ditch System |
Types of Surface Field Drainage System or Open Drains |
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− This resembles terracing in that thedrainage ditches are constructedaround the slope on a uniform gradeaccording to the land topography.The ditches should be constructedacross the slope as straight andparallel as the topography permits. |
•Interception or Cross-slope System. |
Types of Surface Field Drainage System or Open Drains |
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− This is suitable on flat, poorly drainedsoils that have numerous shallowdepressions. In general, the ditchesare 185 m to a maximum of 370 mapart and the land in between theparallel ditches is sloped and smoothedto eliminate any minor depressions orobstructions to the overland flow of thewater. |
• Diversion or Parallel Ditch System. |
Types of Surface Field Drainage System or Open Drains |
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−This system is used in rollingtopography where drainage isnecessary only in smallvalleys. |
•Natural or Random System. |
Types of Surface Field Drainage System or Open Drains |
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−Used if the entire area is to bedrained and is usually moreeconomic. Laterals enter thesubmain from one side only tominimize the double drainagethat occurs near the submain. |
•Gridiron Layout. |
Types of Surface Field Drainage System or Open Drains |
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− The submain is laid in adepression and the laterals jointhe submain from each sidealternately. The land along thesubmain is double drained, butsince it is in a depression, itprobably requires more drainage. |
•Herringbone Pattern. |
Types of Surface Field Drainage System or Open Drains |
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− This system is often used if thebottom of the depression iswide since it reduces thelengths of the laterals andeliminates the break in slope ofthe laterals at the edge of thedepression. |
•Double-main System. |
Types of Surface Field Drainage System or Open Drains |
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−This is used if the main source ofexcess water is drainage from hilllands. The drains are placedalong the toe of the slope toprotect the bottom land. |
•Intercepting Drain. |
Types of Surface Field Drainage System or Open Drains |
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−This system is adopted to minimizethe exposure of the laterals to thehazard posed by root of trees whicheasily enter the open joints ofunderdrains. Mains and lateralswere kept well away from trees. |
•Arrangement to avoid trees. |
Types of Surface Field Drainage System or Open Drains |
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In highly permeable soils underlain by animpervious layer or compact clay of lowpermeability, the groundwater flow is essentiallyhorizontal towards the drains. To simplify theillustration, the source of water flowing toward thedrain is considered a reservoir as shown in thefollowing figure. |
Drain Depths and Spacing |
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- an irrigation system that ismanaged by a bonafide Irrigators’ Association |
1. Communal Irrigation System (CIS) |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- the composite parts of the irrigation system that divertwater from natural bodies of water such as rivers, streams, and lakes |
2. Headworks |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- lands which display marked characteristics justifyingthe operation of an irrigation system |
3. Irrigable Lands |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- lands serviced by natural irrigation or irrigationfacilities. These include land where water is not readily available asexisting irrigation facilities need rehabilitation or upgrading or whereirrigation water is not available year-round |
4. Irrigated Lands |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- a system of irrigation facilities coveringcontiguous areas |
5. Irrigation System |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- an association of farmers within acontiguous area served by a National Irrigation System orCommunal Irrigation System |
6. Irrigators’ Association (IA) |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- the channel where diverted water from a sourceflows to the intended area to be irrigated |
7. Main Canal |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- a major irrigation systemmanaged by the National Irrigation Administration |
8. National Irrigation System (NIS) |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- composite facilities that permitentry of water to paddy areas and consist of farm ditches andturnouts |
9. On-Farm Irrigation Facilities |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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- the channel connected to the main canalwhich distributes irrigation to specific areas |
10. Secondary Canal |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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a tube or shaft vertically set into theground for the purpose of bringing groundwater to the soil surfacefrom a depth of less than 20 meters by suction lifting |
11. Shallow Tubewell (STW) - |
Irrigation Terms (RA 8435 or The Agricultureand Fisheries Modernization Act of 1997) |
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The water is applied to the land through a series of long, narrow channels |
Furrow Irrigation |
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The water flows down the slope in small furrows called corrugations or rills used to germinate drill-seeded or broadcasted crops. |
Corrugation Irrigation |
Types of Furrow Irrigation |
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Zigzag Furrow |
This type of furrow irrigation shall increase the length that the water must travel to reach the end of the irrigation run thus, reducing the average slope and velocity of the water |
Types of Furrow Irrigation |
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• Water is supplied to each furrow from the field canal, using siphons or spiles. If available, a gated pipe is used. Figure 10 and Figure 11 show the direct application of water into each furrow. |
Direct Application |
Operation of Furrow Irrigation |
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It involves irrigating alternate furrows rather than every furrow. Small amounts applied frequently in this way are usually better for the crop than large amounts applied after longer intervals of time |
Alternate Furrow Irrigation |
Operation of Furrow Irrigation |
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Advantages of Furrow Method |
• The method is quite suitable for row crops such as maize, cotton, potatoes, sugar cane, sugar beet, groundnut, tobacco, etc. • The evaporation losses are smaller because only a part of the land comes in contact with water. The puddling of ng heavy clayey soil is less in the furrows method. Hence, it is possible to cultivate soon after irrigation. • There is no wastage of land for the construction of the field channels required in other methods. • The cost of land preparation is less • Suitable for water-logging sensitive crops like maize |
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Disadvantages of Furrow Method |
• Hassle maintaining water flow. Experience and soil surface evaluation is required to set the number of gates opened or tubes set. Otherwise slow water advance or surface runoff can occur. • Not Suitable for sandy soil. • Salts are accumulated in ridges of soil between the furrows. Re-plowing the field for each new crop can redistribute the accumulated salinity. • The movement of farm equipment is difficult in the furrow fields. • Initial filed preparation labor cost is high. • Not suitable for some crops |
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BORDER IRRIGATION |
a type of surface irrigation wherethe field is divided into strips separated by borderridges running down the gradient of the field. Thearea between the ridges is flooded during irrigation. |
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Graded border |
The border strips have some slope in the direction of irrigation, and the ends usually are not closed |
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The border strips have no slope in the direction of irrigation, and they are closed at the ends. |
Level Border |
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small borders no wider than the width of the grading equipment blade. The earth that spills around the blade forms the ridges. The stream size used is only large enough to insure complete coverage of the border strip, primarily used to irrigate grasses |
Guide border |
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level – nearly level strips or areas of predetermined size. Small dikes or levees surround the strips and are constructed longitudinally on the contour. Typically used with rice but has been adapted to the irrigation of pasture grasses, hay crops, small grains, and some row crops |
Contour |
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The border ditch system uses a ditch as a divider between individual strips. The ditch carries irrigation water which is applied at different locations along the entire length of the field. Border ditch irrigation is applied for water application to narrow-row crops, notably grain cereal, annual and perennial grasses. However, it can be used also for water application to other crops in combination with ridge tillage |
Border ditch |
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This is usually applied to large borders where the end borders are provided with openings to accommodate free flow of water for drainage. |
Open-end Border System |
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This is usually applied to small borders where the end borders restrict the further downward flow of water. |
Blocked-end Border System - |
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All close-growing, non-cultivated, sown or drilled crops, except rice and other crops grown in ponded water can be irrigated by border irrigatio |
Crop |
Design Criteria |
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Areas shall have slopes of less than 0.5%. For nonsod crops, slopes of up to 2% may be acceptable and slopes of 4% and steeper forsod crops |
Topography |
Design Criteria |
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The soil shall have a moderately low to moderately highintake rate which is 7.6 mm/hr to 50 mm/hr. Coarse sandy soils with extremely high and those with extremely low intake rate shall be avoided. |
Soil Type |
Design Criteria |
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The stream size shall be large enough to adequately spread water across the width of border |
Stream Size |
Design Criteria |
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A larger irrigation depth shall be aimed by making theborder strip longer in order to allow more time for the water to reach the end of the border strip. |
Irrigation Depth |
Design Criteria |
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The width of borders shall be a multiple of thefarm machinery used in the field. |
Cultivation Practices |
Design Criteria |
